An origin of infinite range dipole-dipole correlations in soft matrices with off-center impurities: K1-xLixTa1-yNbyO3 and other systems

Abstract

A model of cooperative behaviour for K1-xLixTa1-yNbyO3 (KLTN) and for other disordered systems like ferroelectric relaxors is considered from the point of view of contribution of infinite-range dipole-dipole interactions. It is shown that a local piezoeffect for off-center impurities in crystals with rather high electrostriction is responsible as origin of a infinite-range electric dipole-dipole interaction via elastic fields as well as for a co-existence of ferroelectric and glass-like states with reentrant glass effect.